Research progress with the severe acute respiratory syndrome coronavirus 2 Delta variant

The global outbreak of coronavirus disease 2019 (COVID-19) has affected more than 200 million people worldwide, caused millions of deaths, and has threatened global economic stability. Vaccines against severe acute respiratory syndrome coronavirus 2, the causative agent of COVID-19, have been developed, and the rollout of widespread vaccination has curbed the epidemic in many countries. However, variants of the virus, including the Delta variant, have emerged that have triggered new rounds of infection. In this review, we discuss the epidemiological characteristics, pathogenicity, clinical symptoms, laboratory tests, and imaging manifestations of the Delta variant, with the aim of offering new insight into strategies for the early detection, diagnosis, and treatment of disease caused by this coronavirus variant.